Wire active alert filtering into HTTP

internal/adapters/inbound/httpapi/endpoints_test.go

@@ -30,6 +30,7 @@ type fakeService struct {
 	weatherStoryRun   *model.WeatherStoryRun
 	weatherStory      *model.WeatherStory
 	alerts            *model.WeatherAlertRun
+	activeAlertAt     []time.Time
 	outlookRun        *model.WeatherOutlookRun
 	outlookFilters    []app.OutlookFilter
 	conditions        *app.CurrentConditions
@@ -64,6 +65,11 @@ func (s *fakeService) LatestAlertRun(context.Context) (*model.WeatherAlertRun, e
 	return s.alerts, s.err
 }
 
+func (s *fakeService) LatestActiveAlertRun(_ context.Context, activeAt time.Time) (*model.WeatherAlertRun, error) {
+	s.activeAlertAt = append(s.activeAlertAt, activeAt)
+	return s.alerts, s.err
+}
+
 func (s *fakeService) LatestConvectiveOutlook(_ context.Context, filter app.OutlookFilter) (*model.WeatherOutlookRun, error) {
 	s.outlookFilters = append(s.outlookFilters, filter)
 	return s.outlookRun, s.err
@@ -315,6 +321,82 @@ func TestAlertsUSUnitsKeepSchema(t *testing.T) {
 	}
 }
 
+func TestAlertsRouteRegistered(t *testing.T) {
+	def := definitionForPath(t, Definitions(&fakeService{}), "/alerts/active")
+	if len(def.Methods) != 1 || def.Methods[0] != http.MethodGet {
+		t.Fatalf("expected GET definition, got %+v", def.Methods)
+	}
+}
+
+func TestAlertsHandlerPassesCurrentUTCInstant(t *testing.T) {
+	now := time.Date(2026, 6, 11, 7, 30, 0, 0, time.FixedZone("LOCAL", -5*60*60))
+	setAlertNowForTest(t, now)
+	svc := &fakeService{
+		alerts: &model.WeatherAlertRun{AsOf: time.Now().UTC()},
+	}
+	h := newHandler(t, svc, "/alerts/active")
+
+	w := httptest.NewRecorder()
+	req := httptest.NewRequest(http.MethodGet, "/alerts/active", nil)
+	h.ServeHTTP(w, req)
+
+	if w.Code != http.StatusOK {
+		t.Fatalf("expected 200, got %d", w.Code)
+	}
+	if len(svc.activeAlertAt) != 1 {
+		t.Fatalf("expected one active-alert service call, got %d", len(svc.activeAlertAt))
+	}
+	want := now.UTC()
+	if !svc.activeAlertAt[0].Equal(want) {
+		t.Fatalf("expected activeAt %v, got %v", want, svc.activeAlertAt[0])
+	}
+	if svc.activeAlertAt[0].Location() != time.UTC {
+		t.Fatalf("expected UTC location, got %v", svc.activeAlertAt[0].Location())
+	}
+}
+
+func TestAlertsNoDataReturnsNullEnvelopeData(t *testing.T) {
+	h := newHandler(t, &fakeService{}, "/alerts/active")
+
+	w := httptest.NewRecorder()
+	req := httptest.NewRequest(http.MethodGet, "/alerts/active", nil)
+	h.ServeHTTP(w, req)
+
+	if w.Code != http.StatusOK {
+		t.Fatalf("expected 200, got %d", w.Code)
+	}
+
+	var payload struct {
+		Data *json.RawMessage `json:"data"`
+	}
+	if err := json.Unmarshal(w.Body.Bytes(), &payload); err != nil {
+		t.Fatalf("decode envelope: %v", err)
+	}
+	if payload.Data != nil {
+		t.Fatalf("expected data null, got %s", string(*payload.Data))
+	}
+}
+
+func TestAlertsTextRendersEmptyActiveSet(t *testing.T) {
+	h := newHandler(t, &fakeService{
+		alerts: &model.WeatherAlertRun{
+			AsOf:   time.Date(2026, 6, 11, 12, 0, 0, 0, time.UTC),
+			Alerts: []model.WeatherAlert{},
+		},
+	}, "/alerts/active")
+
+	w := httptest.NewRecorder()
+	req := httptest.NewRequest(http.MethodGet, "/alerts/active?format=text", nil)
+	h.ServeHTTP(w, req)
+
+	if w.Code != http.StatusOK {
+		t.Fatalf("expected 200, got %d", w.Code)
+	}
+	if !strings.Contains(w.Body.String(), "Alerts: 0") {
+		t.Fatalf("expected empty alert count in text body, got %q", w.Body.String())
+	}
+}
+
 func TestObservationUSUnitsWithXMLFormat(t *testing.T) {
 	h := newHandler(t, &fakeService{
 		observation: &model.WeatherObservation{
@@ -1265,17 +1347,24 @@ func TestPrecisionValidationRange(t *testing.T) {
 	}
 }
 
-func TestAlertsRejectPrecisionQueryParameter(t *testing.T) {
+func TestAlertsRejectUnsupportedQueryParameters(t *testing.T) {
 	h := newHandler(t, &fakeService{
 		alerts: &model.WeatherAlertRun{AsOf: time.Now().UTC()},
 	}, "/alerts/active")
 
-	w := httptest.NewRecorder()
-	req := httptest.NewRequest(http.MethodGet, "/alerts/active?precision=1", nil)
-	h.ServeHTTP(w, req)
+	for _, rawURL := range []string{
+		"/alerts/active?precision=1",
+		"/alerts/active?tz=CDT",
+		"/alerts/active?TZ=CDT",
+		"/alerts/active?bogus=1",
+	} {
+		w := httptest.NewRecorder()
+		req := httptest.NewRequest(http.MethodGet, rawURL, nil)
+		h.ServeHTTP(w, req)
 
-	if w.Code != http.StatusBadRequest {
-		t.Fatalf("expected 400, got %d", w.Code)
+		if w.Code != http.StatusBadRequest {
+			t.Fatalf("%s: expected 400, got %d", rawURL, w.Code)
+		}
 	}
 }
 
@@ -2263,7 +2352,7 @@ func testRenderers(t *testing.T) *render.Registry {
 		"outlooks_convective.txt.tmpl":     "Convective Outlook\n{{if .Data}}Outlooks: {{len .Data.Outlooks}}\nDiscussions: {{len .Data.Discussions}}{{range .Data.Discussions}}\nDiscussion: {{.Discussion}}{{end}}{{else}}No convective outlook data available.{{end}}",
 		"weatherstories.txt.tmpl":          "Weather Stories",
 		"weatherstories_latest.txt.tmpl":   "Latest Weather Story",
-		"alerts_active.txt.tmpl":           "Alerts text",
+		"alerts_active.txt.tmpl":           "{{if .Data}}Active Alerts\nAlerts: {{len .Data.Alerts}}{{else}}No active alerts data available.{{end}}",
 		"conditions_current.txt.tmpl":      "Conditions text",
 	} {
 		tmpl, err := template.New(name).Parse(body)
@@ -2297,6 +2386,13 @@ func setOutlookNowForTest(t *testing.T, now time.Time) {
 	t.Cleanup(func() { outlookNow = original })
 }
 
+func setAlertNowForTest(t *testing.T, now time.Time) {
+	t.Helper()
+	original := alertNow
+	alertNow = func() time.Time { return now }
+	t.Cleanup(func() { alertNow = original })
+}
+
 func testOutlookRun() *model.WeatherOutlookRun {
 	issuedAt := time.Date(2026, 6, 11, 12, 0, 0, 0, time.UTC)
 	discussionUpdatedAt := issuedAt.Add(30 * time.Minute)